Electrical probe



Feb. 9, 1960 FLEcK 2,924,213

ELECTRICAL PROBE Filed March 17, 1958 INVENTOR HENPY/ LECK ATTORNEYS.

United States Patent ELECTRICAL PROBE Henry Fleck, New York, N.Y.

Application March 17, 1958, Serial No. 722,012

1 Claim. (Cl. 128-21) This invention relates to the art of recording andmore particularly to a probe for picking up minute electricalalterations occurring in muscle fibres as an aid in the determination ofdefects therein.

As conducive to an understanding of the invention, it is noted thatwhere it is desired to record action potentials, i.e., electricalalterations occurring in a single active muscle fibre, to determine thecondition thereof, it is necessary that the wave pattern caused by suchelectrical alterations from a muscle fibre of unknown condition becompared with the wave pattern from a muscle fibre of known or healthycondition which acts as a standard.

Where a probe is inserted into the body and the probe has two electrodesacross which the electrical alteration or potential change is developed,as electrical impulses moving through muscle fibres pass the electrodes,if the dimensions of the electrodes are relatively large and engage morethan one active muscle fibre, due to the interaction of the electricalimpulses from the plurality of muscle fibres, no standard wave patterncan be developed.

Furthermore, where the probe of the above type is inserted into the bodyof the person whose muscle fibres are to be tested, and more than onemuscle fibre is engaged by the electrodes, the resultant wave patternwill also have no utility in determination of disease or deteriorationof any single muscle fibre, due to interaction of the electricalimpulses from the plurality of muscle fibres engaged by the electrode.

Where, in an attempt to minimize the area of the electrodes, a pair ofWires are passed longitudinally through the bore of a needle to theconventional beveled entry end thereof, as the ends of the wires mustconform to the bevel at the end of the needle so that they do notprotrude andn'p the tissue as the needle is forced through the skin, theends of the wires will have a substantially oval contour providing awider contact area than would be provided with a circular end ofdiameter equal to the minor axis of the oval, with the disadvantagesabove set forth.

It is accordingly among the objects of the invention to provide anelectrical probe that may readily be fabricated at relatively low cost,and is strong and durable and not likely to become deranged in use andthat may readily be inserted into tissue of a patient and which haselectrodes that have a minimum spacing therebetween and a minimumsurface area and do not protrude beyond the surface of the needle sothat they will not rip the tissue of the patient, as the needle isinserted, and which will permit recording of electrical alterationsoccurring in a single active muscle fibre.

According to the invention, these objects are accomplished by thearrangement and combination of elements hereinafter described andparticularly recited in the claim.

In the accompanying drawings in which are shown one or more of variouspossible embodiments of the several features of the invention,

Fig. 3 is an enlarged detail view showing the electrodes.

Referring now to the drawings, the probe may comprise a conventionalhypodermic needle 11 which has a bore 12 extending longitudinallytherethrough, the entry end of the needle being beveled to a sharp pointas at 13 to facilitate entry through the tissue of the patient.

The needle 11 adjacent its entry end 13 has an opening or bore 14-extending laterally into the longitudinal bore 12.

Extending through the bore 12 is a pair of insulated wires 15,preferably of the enamel coated type and of extremely small diameter inthe order of 30 microns. The wires 15 also extend through the lateralbore 14 and are cut oil flush with the outer surface of the needle atright angles to the axis of the wire to define two circular electrodes16 and 17 of uniform diameter.

In order to retain the electrodes 16, 17 in fixed position, the bores 12and 14 are filled with suitable material such as plastic 18 or the like.I

With the construction above described, since the surface area of thecircular electrodes 16, 17 is very small and since the interelcctrodedistance or spacing therebetween is also very small, being limited onlyby the thickness of the insulation on the wires, which is in the orderof one micron, it is apparent that the potential change between the twoelectrodes, as electrical impulses pass through a single muscle fibrepast the electrodes, can be ascertained.

The probe thus described is used in recording the wave pattern resultingfrom the potential change across the two electrodes as electricalimpulses pass through a single known healthy muscle fibre.

By making a relatively large number of tests an average wave patternresulting from a corresponding number of healthy individual musclefibres can be determined and used as a standard against which iscompared the wave pattern from a single unknown muscle fibre toascertain deterioration or disease thereof.

As many changes could be made in the above article, and many apparentlywidely difierent embodiments of this invention could be made withoutdeparting from the scope of the claim, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

As an article of manufacture, a needle having a bore extendinglongitudinally therethrough, said needle being pointed at one end andhaving a lateral bore between its ends extending into said longitudinalbore, a pair of insulated wires extending through said longitudinal boreand the lateral bore, the ends of said wires extending through saidlateral bore being circular in cross section and flush with the outersurface of said needle and defining a pair of electrodes spaced by adistance substantially equal to the thickness of the insulation on saidwires, and means to retain said electrodes in fixed position in saidtransverse bore.

References Cited in the file of this patent UNITED STATES PATENTS164,184 Kidder June 8, 1875 2,763,935 Whaley et a1. Sept. 25, 19562,816,997 Conrad Dec. 17, 1957

